In the cut-throat world of financial trading, Angie Long is a natural. Promoted to head JPMorgan's high-yield credit derivative trading desk at 29, her clients and colleagues describe her as "a force of nature in her markets" and "one of the best strategic thinkers on the street". And until last year, says one client, few could have imagined her doing anything else.

Until, that is, she became a mother. In January 2006, three months after her daughter was born, Ms Long returned to the trading desk. A month later, she was ready to resign.